Rock drill



J. E. RENFER Jan. 9, 1934.

ROCK 'DRILL 2 Sheets-Sheet l Filed Feb. 5, 1951 @iii LW Jan. 9, 1934.

J. E. RENFER 1,942,730

ROCK DRILL Filed Feb. 5, 1931 2 Sheets-Sheet 2 iiiiim 52 Patented Jan. 9, 1934 UNITED STATES islam ROCK DRILL John E. Renfer, Cleveland, Ohio, assignor to The Cleveland Rock Drill Company, Cleveland, Ohio, a corporation of Ohio Application February 5,

7 Claims.

This invention relates broadly to fluid actuated tools but more particularly to 'a blowing device for rock drills of the hammer type.

One object of this invention is to incorporate, in a fluid actuated rock drill, means for providing an uninterrupted supply of motive fluid to the drill steel for cleaning the drilled hole.

Another object of this invention is to control the blowing mechanism with the main throttle valve used for regulating the admission of motive fluid to the machine, thus simplifying the manufacture as well as the operation of the device.

Another object of this invention is to provide a blowing mechanism to furnish a great amount of fluid to the drill steel to eiiectuate the ejection of the cuttings or extraneous matter from an unusually deep hole whichV is being drilled.

Another object of this invention is to construct a rock drill embodying a blowing device which is simple in operation, sturdy of structure and economic of manufacture.

Other objects and advantages reside in the specific construction and aggroupment of the elements peculiar to this structure as will become apparent4 from a more complete examination of this specification wherein there are` assembled and pointed out certain combinations of parts and specific constructions indicative of the scope and spirit of the invention.

In the drawings, wherein like reference characters designate like parts throughout the several views.

Figure 1 is a central longitudinal `section through a rock drill embodying the present invention, the valvular and reciprocable elements being shown in their normal operating position.

Figure 2 is a sectional view similar to Figure 1, illustrating the arrangement of the valve and the various elements of the drill wheny the apparatus is adjusted to blow dust and extraneous matter from the hole being drilled. A

Figure 3 is a transverse sectional yview taken on the line 3 3 in Figure l, illustrating the locking device for the throttle valve.

Figure 4 is a sectional end view taken on the line Vfl-f-i in Figure 3.

Figure 5 is a transverse sectional view taken on the line 5-5 in Figure 3, illustrating the throttle valve in its blowing position.

Figures 6-9 inclusive are transverse sectional views taken on the line 6--6 in Figure 3,*showing the four different positions of the throttle valve.

Figures-1013 inclusive are views similar to 1931. Serial No. 513,669

Figures 6-9 inclusive, respectively, but taken on the line 10-10 in Figure 3.

Figures lll-17 inclusive are views similar to Figures 6-9 inclusive, respectively, but taken on the line lll-14 in Figure 3.

The rock drill shown in the drawings comprises a cylinder 10, having a piston 11 reciprocably mounted therein, and a front end member 12, adapted to receive the hollowed drill steel (not shown). The piston 10 is formed with a stem 13, the end portion of which is splined and engageable with the vfront end member 12. The free end of the stem 13 is adapted to abut the shank of the drill steel, this structure being in accordance with the design customarily employed in machines of this type. f

Associated with the cylinder 10 is aratchet mechanism comprising a toothed ring 14, and a splined stem 15 organized with a plurality of pawls 16 to engage with the ratchet ring 14. The free end of the stem 15 is maintained within the head of the piston 11 in an opening of complemental configuration. The assembly of this ratchet mechanism and its appurtenances effectuates a rotary movement of the piston and in turn of the drill steel during the reciprocating movement of the piston.

Associated with the cylinder 10 is a'valve block i7, formed with a plurality of passage ways through which motive fluid is admitted to the cylinder above and below the zone of travel Vof the piston 11. Y

J ournaled within the valve block is a throttle Valve 18, formed with a cylindrical body 19 and an integral handle 20, defining at their intersection an annular flange 21. The flange 21 is provided with a plurality of radially disposed recesses 22, 60, 61 and 62, adapted to engage a stop pin 23. The throttle valve 18 is secured in its seat by the tension of a compression spring 24 disposed at the outer end of the valve and maintained in position by the screw threaded plug 25, formed with a tapered seat 26 engaging the regular air'connection elbow pipe 27.

Within the valve block 1'? is an oil reservoir 28 admitting lubricant into the pressure fluid through a restricted aperture (not shown) and consequently to every working part of the machine. The oil reservoir can be filled or emptied by removing a screw threaded plug 29.

Adjacent the valve block 1'7 and secured to the machine by a pair of side rod bolts (not shown) is a back head 30, organized to receive a cross handle grip 31.

The throttle valve 18 is arranged to occupy -four different positions to eiTect four diierent operations of the drill. In order to clearly illustrate the construction and operation of the parts, Figures 6-17 inclusive are arranged on sheet II of the drawings in three vertical and four horizontal rows, the vertical rows showing corresponding sections through the throttle valve with the Valve in the four different positions, and the horizontal rows showing diiierent sections through the valve in each position. Figures 6, 10 and 14 show the valve turned to the full throttle position, and admitting the maximum ow of fluid tothe cylinder to reciprocate the piston. Figures 7, 11 and 15 show the valve in the half throttle position for partially restricting the ow of iiuid to the cylinder. Figures 8, 12 and 16 show the throttle valve closed. Figures 9, 13 and 17 illustrate the valve in the hole blowing position. l

A slide valve 32 is reciprocably mounted in the valve :block 17 and is arranged to distribute `the motive uid to the opposite ends of the cylinder. This'valve comprises a cylindrical body having pressure flanges 33 and 34 disposed on its opposite ends and an intermediate annular rib 35, the rib being arranged to alternately admit uid to veins 36 and 37 formed in the body of the valve block 17 .and leading to the opposite ends of the cylinder. Motive fluid is admitted to the valve block in normal .operation of the .drill through the connection elbow 27, a passage 38 formed in the throttle valve 1.8, double channel 39, and an inlet vein 40, and enters one oi the outlet veins .as for instance the vein 36, in Figure 1, and flows to the front end of the cylinder through port 4l, thus driving the piston 11 rearwardly. The piston moving rearwardly will uncover a kick port 42 and admit pressure fluid to the front pressure flange .34 of the valve 32, the rear pressure flange `33 being open to katmosphere through a duct 43 .Csee Figure 6), port 44 in the throttle valve 19, and exhaust passage 45, and the valve V32 will thereby be moved to its rearward position. After uncovering the kick port 42, the piston continuing its rearward movement will uncover the exhaust port 46, .and consequently allow the pressure fluid in the front cylinder chamber to escape to atmosphere through ports 47, throttle valve passage 48, and exhaust port 49 .(.see Figure 10). IElhe valve `32 being now in the position shown in Figure 2, motive fluid will vbe admitted to the rear end of the piston l1 from the .outlet vein '37 through port 65, ratchet mechanism 16, and port 50 thus actuating the piston 11 Vin its forward travel to deliver its blow to the cutting tool. During its forward movement, the piston will first -uncover the kick port 51, thus admitting pressure to the rear pressure flange 33. The front pressure iiange 34 being open to atmosphere through duct 52, throttle valve passage 53, and exhaust lport 54, the valve 32 will be moved to its forward position. After uncovering the kick port 51, the piston continuing its forward movement will uncover the exhaust port 46, thereby allowing the yescape vof pressure from the rear cylinder chamber to atmosphere by way of port 47, valve passage 48 and exhaust port 49.

The front end of the cylinder 10 is capable of -commLmica-tion with the throttle valve through a passage and a port 59, while the rear end of the cylinder 1Q is capable of communication with the throttle Valve through a duct 56. The purpose of these passages will be set forth hereinafter.

It has been found necessary when the operator starts the drilling of a hole to have the piston 11 deliver a very light blow to the drill steel. For that purpose the operator may turn the throttle valve 19 a short distance from closed position until recess engages the stop in 23, the throttle valve then being in the position shown in Figures 7, l1 and 15. In this position motive fluid is admitted to the inlet vein 40 through a port 57 (see Figure 11) of smaller cross sectional area than the double channel 39, consequently admitting into the cylinder 10, a small amount of pressure iiuid, suilicient to reciprocate the piston 11 and to deliver a light impact upon the drill steel. In vthat position of the throttle valve 19, the reciprocation ofthe piston takes place in the same manner as described previously, the two ducts 43 and 52, being open to atmosphere through the ports 44, 45, 53 and 54 respectively, as illustrated in Figure 7. The front and rear cylinder chambers are alternately exhausted to atmosphere through ports 47, 48, and 49, in the manner previously explained.

To shut oiT the machine, the throttle valve may be moved until the recess 61 engages with the stop pin 23. The throttle valve is then in the position shown in Figures 8, 1'2 and 16, and prevents any motive fluid from entering the inlet vein 40 in the valve block 17, as illustrated in Figure 12- In this position of the throttle valve the ducts 43 and 52 are out of registration with the exhaust ports 45 and .54, as illustrated in Figure 8.

To effect the hole blowing operation, the throttle valve is turned to allow the engagement ofthe recess 62 with the stop pin 23. During this rotative movement of the throttle valve, motive iiuid is first admitted to the front end of the cylinder l0, through port 38, duct 58, port 59, land passage 55, as illustratedin Figure 17, and moves the piston 11 rearwardly a sumcient distance to permit the registration of the exhaust port `46 with the front end of the-cylinder. At the end of the rotative movement of the valve 19, the double channel 39 is in registration with the .exhaust port 47 (see Figure 13), thus admitting a lfull ow of compressed air to the front end of the cylinder 10, and tending to move the 'piston 1l to the limit of its rearward stroke. However, due to an inevitable -clearance around the different working parts of the mechanism, motive uid will Vaccumulate inthe rear end of the cylinder chamber and prevent the piston 11 from reaching its extreme rearward position. It is therefore necessary to vent the rear of the cylin- -der through port 50, ratchet mechanism 16., and ports 56, 48 and 49, as illustrated in Figure 5. When the piston 11 reaches its extreme rearward position, the motive fluid in the front end of the cylinder ows past the splined portion of the stem 13 to the hollow drill steel to clean the hole being drilled. It will be noted by referring to Figures 14, 15 and 16 that the ports 58 and 59 are only in registration when the throttle valve 19 is in the blowing position as shown in Figure 17. It will further be noted that during the blowing operation, the two kick ports 42 and 51 are out of registration with the two exhaust ports 45 and 54 thus preventing a loss of motive fluid which is admitted to the opposite pressure areas 33 and 34 of the valve 32 through the ports 51 :if

and 42 during the blowing operation.

Although the foregoing description is necessarily of a detailed character in order'that the invention may be completely set forth, it is to be understood that the specic terminology is not intended to be restrictive or confining and that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder, a piston reciprocable therein, and a blowing device comprising a uid supply passage, a valve in said passage, a pair of conduits leading from said valve to said cylinder, said valve being capable of rotation into blowing position, passages within said valve capable of communication with one of said conduits to admit motive fluid to one end of said cylinder to move the piston in one direction during the initial part of such rotation and capable of communication with the other of said conduits to admit iluid therethrough in blowing position after the piston has been so moved preventing thereby the reciprocation of said piston.

2. In a blowing device for rock drill, a cylinder and a piston, a valve for admitting pressure fluid to said cylinder to effect the blowing of the hole being drilled, and means within said valve for admitting pressure fluid into one end of said cylinder to move said piston in one directionprevious to the admission of the said pressure fluid to effect the blowing of said hole.

3. In a iiuid actuated tool, a cylinder and a piston reciprocating therein, a throttle valve, a valve casing formed with a Valve chamber having a valve slidable therein, inlet and outlet passages Within said cylinder for admitting or exhausting motive uid to and from both ends of said cylinder, another passage for exhausting one end of said cylinder and a further passage for admitting motive fluid to the other end of said cylinder.

4. In a blowing device for rock drill, a cylinder and a piston, inlet ports toward each end of said cylinder for admitting pressure therein during the normal reciprocation of said piston, exhaust passage intermediate said inlet ports for exhausting pressure iiuid from said cylinder during said normal operation, and means for admitting pressure fluid through said exhaust passages into said cylinder preventing thereby the reciprocation of said piston and effecting the blowing of the hole being drilled.

5. In a blowing device for rock drill, a cylinder and a piston, a valve, passages Within said valve and cylinder for admitting pressure fluid to one side of said cylinder to eiect the blowing of the hole being drilled and other passages within said valve and cylinder for admitting pressure fluid to said side of said cylinder previous to the admission of said first mentionedpressure uid affording thereby the removal of said piston from said side of said cylinder.

6. In a blowing device for rock drill, a cylinder having a piston reciprocable therein, inlet and outlet passages within said cylinder for conveying pressure iluid into and out of said cylinder to normally operate said piston, means for admitting a restricted amount of pressure fluid into one end of said cylinder to lift said piston away from said outlet ports and subsequently admit pressure uid to said one end of said cylinder Vthrough said outlet ports for maintaining said piston in the other end of said cylinder and effecting the blowing of the hole being drilled.

7. In a blowing device for rock drill, a cylinder having a piston reciprocable therein, inlet ports opening toward the ends of said cylinder for admitting pressure fluid therein during the normal operation of said piston, a passage opening into said cylinder at a point intermediate said inlet ports, and means for preventing the admission of the pressure fluid through said inlet ports and simultaneously admitting pressure uid into said cylinder through said passage to eiect the blowing of the hole being drilled.

JOHN E. RENFER. 

